JPH03500816A - Particle asymmetry analyzer - Google Patents

Abstract

An apparatus and method which provides a measure of the asymmetry as well as the size of individual fluid borne particles. Laser-light scattering techniques are employed to obtain data on the particles, which is then compared to data on known particle shapes to ascribe an asymmetry factor to the particles.

Description

[Detailed description of the invention] Particle asymmetry analyzer The present invention relates to techniques for the analysis of particles supported in liquids, and in particular to techniques for the analysis of particles supported in liquids. Concerns techniques for testing asymmetry.

For example, research on aerosols, aerosol dispersion and airborne particle pollution control. The investigation includes information on the geometry and symmetry of individual particles, as well as There is a need for rapid measurement of particle size distribution within the range of 1 to 10 microns in diameter.

For example, information about particle geometry and symmetry can be obtained from particles with spherical symmetry. of liquids in the environment containing other non-spherical solid particles. Allows droplets to be counted/monitored. In the context of this specification, the term "grain" "child" is intended to apply to both solid and liquid droplets.

Such techniques typically target individual particles within a sample at a rate of 20,000 particles per second. It is possible to count particles, and to distinguish between spherical particles and non-spherical particles. It would be desirable to be able to separate and count each type. another preference A unique feature is that spherical particles with diameters from 0.5 to 15 microns are available in several size ranges. classification and related classification of non-spherical particles and collection of particle size spectra. In the collection, such non-spherical particles are ignored.

The usual techniques for particle measurement, such as those used in some commercially available instruments, are using the detection and analysis of electromagnetic radiation scattered by the particles. All such devices , using a mechanical mechanism to drive sample air through a "detection volume" However, within that “detection volume”, the transported particles are illuminated by the incident electromagnetic number. It will be done. the radiation scattered by the particles is received by one or more detectors; These detectors convert that energy into an electrical signal, and from this electrical signal, Information is extracted by means of electrical circuits.

The first type of commercially available device collects scattered radiation from a large number of particles simultaneously. is possible, and measures the average particle mass per unit volume of gas or air. or use this information to determine the statistical average size distribution of particulate matter. use

These devices are unable to measure individual particles and are therefore sensitive to particle morphology. No relevant accurate particle counts or information can be given.

A second type of commercially available device uses gas to confine particles to a smaller detection volume. It is possible to use the laminar flow properties of The individual particles are examined by It is possible to make a rough estimate.

Therefore, to some extent, prior art devices cannot provide information regarding particle size and particle counts. That would be it. However, it does not give information about the asymmetry of particles carried in individual fluids. No equipment is available that can do this.

It is therefore possible to analyze particles carried in individual fluids and for example By finding the asymmetry factor in the particles, we can obtain information about the asymmetry of the particles. There is a need for a particle analyzer that can provide

According to one aspect of the invention, a means for delivering a fluid sample in the form of a laminar fluid; means for irradiating said sample with a beam of synchrotron radiation; and means for reflecting and concentrating scattered radiation; means for directing radiation from said radiation collector to display particles; A particle analyzer is provided, the analyzer further comprising: means for obtaining data; , in order to measure the degree of asymmetry of the particles, the obtained data are related to the known shape. It also includes means for comparing the data.

Preferably, the beam of radiation is provided by a laser and the beam of scattered radiation is preferably provided by a laser. The light is preferably emitted by a concave mirror that directs the emitted light into a emitted light collector. reflected by an ellipsoidal mirror. The synchrotron radiation scattered at a low angle is reflected in the ellipsoidal mirror. preferably by a radiation collector in a second chamber leading from an opening in the It is detected by an optical fiber placed concentrically around the scattered beam. after that , the collected radiation is converted into electrical signals, processed and analyzed, and further By comparing the data on known particle shapes, it is possible to determine whether the particles are the cause of the asymmetry. is considered to have the following.

Furthermore, in addition to the asymmetry factor, it is also possible for the particle size to be measured. many particles It can be considered as having an asymmetry factor, and its related The cumulative result of this operation combined with the particle size spectrum is the single Aerial photographic data of particles in the environment can be larger than the data of particles in ! i(thumb print) can also be used to generate J It is.

When investigating sphericity, the criterion for classifying spherical particles is randomly polarized light. It is easily determined as symmetric scattering about the illumination beam axis of circularly polarized or circularly polarized synchrotron radiation. It is possible to be defined. Therefore, some synchrotron radiation collectors are installed radially symmetrically around an axis.

In the case of investigating the degree of asymmetry, the arrangement of the synchrotron radiation collector should be It cannot be the same as the optimal arrangement for analyzing gender. the scattering The design of the chamber makes it possible to achieve the flexibility of the collector shape that is particularly required. , and it must be possible to change the position of the collector at will.

The advantage of this technique is that by using fiber-optic collection optics, the scattering range Same effect as installing almost any number of collectors at any position around the entire circumference. can be easily realized, and without using this technology, the above Accomplishing the task will be mechanically extremely difficult. Therefore its high degree of adaptability Therefore, various detection geometries can be used without the need for mechanical modifications to the scattering chamber itself. metrics can be tested.

A method for measuring asymmetry of particles supported in a fluid according to a second aspect of the invention The law is providing a fluid sample in the form of a laminar flow; irradiating the sample with a synchrotron radiation beam; reflecting the synchrotron radiation to a synchrotron radiation concentrator; A step in which data representing the particles is obtained from a light collector and the degree of asymmetry of the particles is measured. a step of comparing data about the known shape with the obtained data in order to including.

The sample may be an aerosol.

Two embodiments of the invention will now be described with reference to the accompanying drawings as follows: This will be explained as an example of the present invention.

Figure 1 is a schematic side sectional view of a particle analyzer for analyzing spherical particles; Figure 2 is a cross-sectional view of the analyzer along line XX in Figure 1, and Figure 3 is an asymmetry analysis. 1 is a schematic side cross-sectional view of the system; FIG.

Figure 1 illustrates the basic form of the invention in which only spherical particles are analyzed; In this embodiment, an emitting concave reflector 1 is installed at one end of the scattering chamber 2.

At the other end of the scattering chamber 2 and in line with the main axis of the reflector 1, a laser 3 is provided. is mounted and this laser directs the radiation beam 4 between the aperture 5 in the reflector 1 and the reflector. Orient it towards chamber 2 which is on the main axis. The beam 4 passes through the aperture 5 After that, the bead, typically a Rayleigh horn, is Enter Mudump 6.

A sample 1 of laminar air is sampled by a laser beam 4 that crosses the laser beam 4 at right angles at the focal point of a parabolic reflector 1. is guided into the chamber 2 in such a way that the

The particles in sample 7 deflect the radiation from beam 4 onto mirror 1, which The radiation is reflected parallel to the main axis into a radiation collector 8 adjacent to the laser 3. radiation Is the light collector 8 a photomultiplier unit or an optical fiber leading to such a unit? or a lever for guiding synchrotron radiation to the fiber or the photomultiplier unit. It may be a lens.

Three synchrotron radiation collectors 8 are arranged radially around the beam 4, as shown in FIG. It is located in In such an arrangement, the symmetry scattering that confirms the spherical particles is better. It is possible to be directed. In practice, any number of radiation collectors 8 can be used to Preferable particle analyzer according to the present invention that can attribute the symmetry factor of One example is shown below. In this example, the laser 3 is located in the lower part of the chamber 2 and in the opposite direction. It is attached at an angle of 90° to the main axis of the projecting mirror 1. Beam 4 is the reflector reflected onto the main axis of the reflector by a prism or mirror 9 properly placed on the main axis. Ru. In reality, the laser 3 is scattered using a mirror 9 tilted at an appropriate angle on said axis. It can be mounted at almost any position around the chamber 2.

FIG. 3 also shows a scattering chamber 2 with one ellipsoidal skin 9A mirror 10, and the beam The point where 4 and sample 7 intersect is at one focus of this ellipsoidal stage 1&i, and the chamber A collector lens 11 directs the reflected radiation in parallel to a radiation collector 8 at the end of the It is attached near the other focal point of the ellipsoidal reflector. In this position, The intensity distribution is that of the intensity distribution scattered by the particles to about 0.84 of the scattering range. Represents a spatially transformed replica. Figure 1 shows a seam that supplies an air layer at a constant rate. 1 shows a fluid sample 7 delivered in laminar flow by means of an air inlet 12;

When capturing and analyzing synchrotron radiation scattered at a low angle with respect to the direction of dome 4 A certain degree of difficulty arises. At very low angles (1° to 3°), the following The scattered light is canceled by light scattering based on the focusing optical system. overcome this problem The second scattering chamber 13 has a concave surface on the main scattering chamber 2. ) I mirror 1 It is introduced coaxially with the main shaft. Synchrotron radiation collector to collect low angle deflection 8 is suitably placed within this chamber.

FIG. 3 therefore shows a second channel in which the optical fiber 14 is arranged around the beam 4. The bar 13 is shown. The optical fibers 14 may be arranged in a concentric ring around the beam 4. good. This optical fiber 4 electrically transmits the collected emitted light for processing and analysis. It acts as a synchrotron radiation collector for converting into radio waves.

Alternatively, as shown in FIG. 4, this second concave reflecting mirror 14 is usually an ellipsoidal reflecting mirror, has at its second or distal focus the point where beam 4 and sample 7 intersect; It has one emitted light collector 15 at the first or proximal focus. Therefore, it is deflected at a low angle. The directed radiation hits the ellipsoidal reflector and is guided onto the radiation collector 15. It will be done.

The radiation collector 15 may be placed facing the opening 5 on the first chamber. , or placed at an angle of 90° to this direction, as shown in Figure 1. good. The latter arrangement collects relatively more radiation polarized at low angles. However, since only the frontal deflection of the collector will be registered, the radiation Collections will be smaller overall.

Figure 1 shows a filtered constant velocity system supplied around test 11 in actual use. Figure 1 shows how the sample is delivered in a laminar flow by ground air. Therefore The outer part of the sample flows at the same speed as its inner part. Otherwise outside the sample The side portion flows at a slower velocity due to friction with the steady air adjacent to its sample stream. I'm going to do it. In addition to this, it is even more important that the air for the sheath The feeding coaxial tube dynamically moves the particles within its sample to give a laminar flow of particles. Designed to focus. This focuses the particle stream onto the focal point of the reflector. It becomes easier to do so.

One asymmetric particle analyzer operates as follows. produced by gas laser The laser beam entered the chamber at right angles to the axis of the reflector and further 90″″ reflected along the principal axis.

Therefore, by an individual particle in the range of approximately 19° to 145° with respect to its beam axis. The scattered radiation is reflected into a layer of aspheric collection lenses at the rear of the chamber. child The lens collimates the emitted light, and the intensity distribution across this output window is determined by the particle. A spatially deformed replica of the scattered intensity distribution down to approximately 0.84 of the sphere. represent.

For the collected light of the above form, a fiber optic detector to measure the light distribution The position of can be changed at will.

To measure the sphericity of a particle, the detector is placed symmetrically about the axis of the output window. be done.

In this way, fiber optics can be used to cover almost the entire circumference of the entire scattering loop. The same effect as installing almost any number of collectors in any location can be easily achieved. It is possible to

Based on the results of theoretical models and experimental results of scattering patterns of known shapes, particles An algorithm is used to find out which has an asymmetry factor.

Processing of data obtained from particles to measure particle asymmetry can be carried out by e.g. r1tish Transpients such as those produced by Inmos chip manufacturing company It could be handled by a transputer.

One transducer is used for each detection channel. in this way , tasks that were previously performed sequentially on data arriving from each channel are now This can be done simultaneously for all channels, and the data throughput is It would be possible to bring about a significant increase in

Although the invention has been described by way of example only with reference to the accompanying drawings, the accompanying claims Variations and improvements may be made without departing from the scope of the invention as defined in It should be understood that it is possible to

Copy and translation of amendment) Submission (Article 184-8 of the Patent Law) May 1990? Tonya Yoshi, Commissioner of the Patent Office 1) Takeshi Moon 1. Indication of patent application PCT/GB 881009752, title of invention Particles Asymmetry analyzer 3, patent applicant Name United Kingdom 5. Date of submission of amendment: January 9, 1990 The second type of device on the market is more In order to confine the particles to a small detection volume, we use the laminar flow properties in gases, In addition, individual particles can be examined by concentrating the incident electromagnetic radiation in some way. However, it is possible to provide particle counts and possibly estimate the particle size distribution.

Therefore, to some extent, prior art devices cannot provide information regarding particle size and particle counts. That would be it. However, it is possible to provide information about the asymmetry of individual fluid-carrying particles. A device that is capable of analyzing particles carried in individual fluids is not available manually. possible and non-uniformity of particles, e.g. by finding asymmetry factors in individual particles. There is a need for a particle analyzer that can provide information about symmetry.

In accordance with one aspect of the invention, a particle analyzer for use in measuring particle asymmetry is provided. The device is designed to deliver a sample of airborne particles in the form of a laminar fluid. means for randomly polarizing; and at least one means for reflecting the scattered radiation; forward scattering detectors and at least three spherical detectors symmetrically placed around a central axis. means for directing said scattered radiation towards a detector; and means for directing said scattered radiation towards a detector; to obtain data from the detector and to measure the degree of asymmetry of the particles. means for comparing said data with data relating to known shapes in order to It is characterized by:

The scattered radiation is captured by a concave reflector that directs the radiation into a radiation collector. and is preferably reflected by an ellipsoidal mirror. Synchrotron radiation scattered at a low angle is by a radiation collector in a second chamber communicating with an aperture in the ellipsoidal mirror; , preferably by an optical fiber placed concentrically around the non-scattered beam. Served. The collected radiation is then converted into electrical signals, processed and by analyzing and further comparing it with data on known particle shapes. The particles are considered to have an asymmetry factor.

Furthermore, in addition to the asymmetry factor, it is also possible for the particle size to be measured. many particles It can be considered as having an asymmetry factor, and its related The cumulative result of this operation combined with the particle size spectrum is the single Aerial photographic “special 9” data of environmental particles can be larger than the particle data of %(thumb print) can also be used to generate J. be.

When investigating sphericity, the criterion for classifying spherical particles is randomly polarized light. It is easily determined as symmetric scattering about the illumination beam axis of circularly polarized or circularly polarized synchrotron radiation. It is possible to be defined. Therefore, some synchrotron radiation collectors are installed radially symmetrically around an axis.

In the case of investigating the degree of asymmetry, the arrangement of the synchrotron radiation collector should be It cannot be the same as the optimal arrangement for analyzing gender. the scattering The design of the chamber makes it possible to achieve the flexibility of the collector shape that is particularly required. , and it must be possible to change the collector position at will.

The advantage of this technique is that by using fiber optic collection optics, the scattering range Same effect as installing almost any number of collectors at any position around the entire circumference. can be easily realized, and without using this technology, the above Accomplishing the task will be extremely difficult mechanically. Therefore, the appropriate altitude Due to its responsiveness, a variety of detection techniques can be accommodated without the need for mechanical changes to the scattering chamber itself. Ometry ~ can be tested.

A method of measuring particle asymmetry according to the second aspect of the invention comprises: providing a sample of airborne particles in the form of a laminar flow and randomly polarized or circularly polarized light; irradiating the sample with an illuminated laser beam; radially symmetrically placed around a central axis with at least one forward scatter detector; radiation scattered by individual particles toward at least three sphericity detectors; reflecting light and obtaining data representative of the particles from the detector; To determine the degree of asymmetry of the particles, data on the known shape and the obtained The method is characterized in that it includes a step of comparing the obtained data with the obtained data.

The sample may be an aerosol.

Now, two embodiments of the invention will be described below with reference to the accompanying drawings as follows: This will be explained as an example of the invention.

Figure 1 is a schematic side sectional view of a particle analyzer for analyzing spherical particles, Figure 2 is a cross-sectional view of the analyzer along the line X× of FIG. 1, and FIG. FIG.

Copy and translation of amendment) submission form (Article 114-8 of the Patent Law) Commissioner of the Japan Patent Office Yoshi 1) Moon Takeshi 1. Indication of patent application PCT/GB 881009752, title of invention Particles Asymmetry analyzer 3, patent applicant Address: United Kingdom, London, Nis.W.1.A.2.H. B, Whitehall (no address) Name: United Kingdom 4. Representative Yamada Building 5, Shinjuku 1-1-14, Shinjuku-ku, Tokyo, submission of amendment. Date of issue: February 1990, scope of claims (1) A particle analysis device for use in measuring particle asymmetry, providing a sample of particles carried in air in the form of a laminar flow and a randomly polarized or means for irradiating the sample with a circularly polarized laser beam; radially symmetrically placed around a central axis with at least one forward scatter detector; radiation scattered by individual particles toward at least three sphericity detectors; means for directing light and obtaining data from the detector to represent the particles; means and To determine the degree of asymmetry of the particles, data on the known shape and the obtained and means for comparing the obtained data with the data obtained.

(2) Claim 1, wherein the means for directing the emitted light is a concave reflecting mirror. The particle analyzer described in .

(2) The grain according to claim 2, wherein the concave reflecting mirror is an ellipsoidal reflecting mirror. Child analyzer.

'A) The #2 central axis is the foul axis of the concave reflector or ellipsoid reflector. The particle analyzer according to claim 2 or 3.

(ω) Any one of claims 1 to 4, wherein the detector is a photomultiplier tube. The particle analyzer according to any one of the above.

(6) The detector is an optical fiber leading to a photomultiplier tube. A particle analyzer according to any one of claims 1 to 4.

ω　The synchrotron radiation collector may have any shape, and its position may be freely determined. Particle fraction according to any one of claims 1 to 6, characterized in that it can be varied. analysis equipment.

■ A method for measuring particle asymmetry, in which particles are carried in air in a laminar flow. with a randomly polarized or circularly polarized laser beam. irradiating the sample; radially symmetrically placed around a central axis with at least one forward scatter detector; radiation scattered by individual particles toward at least three sphericity detectors; reflecting light and obtaining data representative of the particles from the detector; To determine the degree of asymmetry of the particles, data on the known shape and the obtained and comparing the data with the data obtained.

(■　Emitted light scattered by individual particles is transferred to a light collector by a concave reflector. 9. A method according to claim 8, characterized in that the beam is reflected towards the target.

10. The C0 concave reflector has an ellipsoidal inner surface. How to put it on.

09 The central axis is the reflection axis of the concave reflecting mirror or the ellipsoidal reflecting mirror. The method according to claim 9 or 10.

C3 Any of claims 8 to 11, wherein the detector is a photomultiplier tube. The method described in item 1.

■ The detector is an optical fiber connected to a photomultiplier tube. 12. A method according to any one of claims 8 to 11.

international search report 1s11. , a+Ie-^-ek-God-'-PCT/GB 8B100975

Claims (9)

[Claims] (1) A particle analyzer, means for providing a fluid sample in the form of laminar flow and irradiating said sample with a synchrotron radiation beam; a means for directing the synchrotron radiation scattered by the individual particles to a synchrotron radiation collector; a means for directing means for obtaining data from said synchrotron radiation collector for displaying particles; , In order to measure the degree of asymmetry of the particles, we combine the above data with known shape data. A particle analyzer which also includes means for comparing data. (2) The particle analysis device according to claim 1, wherein the beam of irradiation is provided by a laser. . (3) Claim 1 or 2, wherein the means for directing the emitted light is a concave reflector. The particle analyzer described. (4) The particle analysis device according to claim 3, wherein the concave reflecting mirror is an ellipsoidal reflecting mirror. (5) From claim 1, wherein the synchrotron radiation collector is an optical fiber leading to a photomultiplier tube. 4. The particle analyzer according to any one of 4. (6) The synchrotron radiation collector may have any shape and its position can be freely determined. The particle analysis device according to any one of claims 1 to 5, which may be changed to. (7) A method for measuring the asymmetry of suspended particles in a fluid, the method comprising: a step of giving irradiating the sample with a synchrotron radiation beam; reflecting the emitted radiation onto a radiation collector; A step in which data representing the particles is obtained from a light collector and the degree of asymmetry of the particles is measured. comparing said data with data regarding known shapes in order to How to do it. (8) The method of claim 7, wherein the fluid is an aerosol. (9) A method according to claim 7 or 8, wherein the beam of radiation is provided by a laser.